Field of Invention
The present invention relates drilling machinery, and more particularly to the field related to construction for mineral mining, vertical shaft for building construction, auxiliary class vertical shaft construction.
Description of Related Arts
The current drilling method utilizes large scale vertical shaft machines, which has high degree of mechanization. However, since drilling under reduced pressure is used, gravity guiding, cutterhead pressure and torque are greatly restricted. Accordingly, the drilling efficiency is low and it is difficult to achieve shaft formation rapidly.